Vinyl ether group-containing copolymer, preparation process and use thereof

ABSTRACT

The invention provides a vinyl ether group-containing copolymer, preparation process and use thereof. The copolymer comprises of the structural units represented by the following general formulae I, II and III, wherein, R 1  is O or HN, R 2  is an alkyl group with a carbon atom number of 1-4, cyclohexyl or a group represented by the following general formula IV (m represents a positive integer of 1-3), n is a positive integer of 1-4, the molar numbers of the structural units represented by the general formulae I, H and III are x, y and z, respectively, and x:y:z=3-8:1-4:1-5, the weight average molecular weight of the copolymer is 5000-20000. A color light blocking agent added with the copolymer can increase sensitivity. Furthermore, the copolymer has solubility in an alkaline solution, and thus, the color light blocking agent added with the copolymer has a superior developing property.

CROSS-REFERENCE TO RELATED APPLICATION

This Application is a non-provisional Application of Chinese ApplicationNo. CN 201210546705.4, filed Dec. 14, 2012 in Chinese, the contents ofwhich are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The invention relates to a vinyl ether group-containing copolymer, thepreparation process and use thereof.

BACKGROUND OF THE INVENTION

A color light blocking agent is mainly consisted of a pigment disperseliquid, an alkali soluble film-forming resin, a multi-functional monomerand a photo-initiator (see Chinese Patent Application CN101613276A). Themethacrylic resin is a film-forming resin generally used in a colorlight blocking agent, and has high transparency and resolution. Thereare double bonds in a certain proportion on the side chain of themethacrylic resin, and thus, a polymerization under the action of aradical polymerization initiator may happen among the polymer chains, ora cross-linking reaction with small molecules may happen. Generally, thedouble bonds introduced are methacrylic double bonds and thepolymerization thus happened is a radical polymerization. However, theradical polymerization is apt to be interfered by the polymerizationinhibition of oxygen, resulting in the decreased sensitivity and poordeveloping property of the color light blocking agent sometimes.

SUMMARY OF THE INVENTION

In view of the above problem of the decreased sensitivity and poordeveloping property of the color light blocking agent, the presentinvention provides a vinyl ether group-containing copolymer, itspreparation process, as well a color light blocking agent prepared usingthe same. The specific solutions are as follows.

A vinyl ether group-containing copolymer composed of the structuralunits represented by the following general formulae I, II and III,

wherein, R¹ is O or HN,

R² is an alkyl group with a carbon atom number of 1-4, cyclohexyl or agroup represented by the following general formula IV, with methyl,ethyl or butyrolactone group being preferable,

wherein m represents a positive integer of 1-3,

n is a positive integer of 1-4, preferably, a positive integer of 2-4.

The molar numbers of the structural units represented by the generalformulae I, II and III are x, y and z, respectively, andx:y:z=3-8:1-4:1-5, preferably, x:y:z=4-6:2-3:2-4.

The weight average molecular weight of the copolymer is 5000-20000,preferably, 14000-17000.

The copolymer may be a random copolymer or a block copolymer.

The process for preparing the above copolymer comprises the steps of:

(1) copolymerizing methacrylic acid, a methacrylate represented by thefollowing general formula VI and methacryloyl chloride to obtain acopolymer 1;

(2) adding a vinyl ether represented by the following general formula Vinto the copolymer 1 to obtain the vinyl ether group-containingcopolymer,

wherein, R¹ is O or HN,

R² is an alkyl group with a carbon atom number of 1-4, cyclohexyl or agroup represented by the following general formula IV, in which mrepresents a positive integer of 1-3,

n is a positive integer of 1-4.

The above preparation process can be performed by reacting themethacrylic acid, the methacrylate represented by the general formula VIand the methacryloyl chloride in the presence of an initiator at 50-90°C. for 8-20 hours to obtain the copolymer 1, and then adding dropwisethe vinyl ether represented by the general formula V into the copolymer1 at 35-50° C. over 1-3 hours and reacting for 5-20 hours to obtain thecopolymer of the invention.

The invention further relates to use of the above copolymer in thepreparation of a color light blocking agent.

Furthermore, the invention relates to a color light blocking agentcomprising the above vinyl ether group-containing copolymer.

Preferably, the color light blocking agent further comprises a radicalpolymerization initiator and a cationic polymerization initiator.

Wherein, the radical polymerization initiator is one or more selectedfrom 1-hydroxycyclohexylphenylmethanone,2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-acetone, and2-isopropylthiaanthracenone; and the cationic polymerization initiatoris one or more selected from AlCl₃, BF₃, SnCl₄, PAG-201 (ChangzhouTronly Electronic Material Co. Ltd., with a maximal absorptionwavelength of 301 nm), ZnCl₂ or TiBr₄.

In the vinyl ether group-containing copolymer of the invention, a vinylether type double bond, which can be subjected to polymerization in thepresence of a radical polymerization initiator and a cationicpolymerization initiator, is introduced into the side chain of thepolymer. Because the cationic polymerization is not interfered by oxygengas and the efficiency of polymerization is high, the color lightblocking agent added with this copolymer can increase the sensitivity.Furthermore, because the copolymer of the invention comprisesmethacrylic acid units and thus has a certain degree of acidity, it issoluble in an alkaline solution. Therefore, the color light blockingagent added with the copolymer has a superior developing property.Additionally, the copolymer of the invention comprises a polar group,that is, a carboxyl group, which contributes to the adhesion of thefilm, and thus, the color light blocking agent added with the copolymerof the invention has a superior film-forming property. The copolymer ofthe invention comprises methacrylate units which contribute to theadjustment of the flexibility of the film. Moreover, the raw materialsfor the copolymer of the invention are simply available, the operationprocess is simple, and the cost is relatively low.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to a vinyl ether group-containing copolymercomposed of the structural units represented by general formulae I, IIand III,

wherein, R¹ is O or HN,

R² is an alkyl group with a carbon atom number of 1-4, cyclohexyl or agroup represented by general formula IV (wherein, m represents apositive integer of 1-3, preferably, m is 1). The alkyl group with acarbon atom number of 1-4 includes methyl, ethyl, propyl, iso-propyl,butyl, iso-butyl, tert-butyl. Preferably, R² is methyl, ethyl orbutyrolactone group.

n is a positive integer of 1-4, preferably, a positive integer of 2-4.

The molar numbers of the structural units represented by the generalformulae I, II and III are x, y and z, respectively, andx:y:z=3-8:1-4:1-5, preferably, x:y:z=4-6:2-3:2-4. The weight averagemolecular weight of the copolymer is 5000-20000, preferably,14000-17000.

The copolymer may be a random copolymer or a block copolymer.

The process for preparing the above copolymer comprises the steps of:

(1) copolymerizing methacrylic acid, a methacrylate represented bygeneral formula VI and methacryloyl chloride to obtain a copolymer 1;

(2) adding a vinyl ether represented by general formula V into thecopolymer 1 to obtain the vinyl ether group-containing copolymer,

wherein, R¹ is O or HN,

R² is an alkyl group with a carbon atom number of 1-4, cyclohexyl or agroup represented by general formula IV, in which m represents apositive integer of 1-3,

n is a positive integer of 1-4.

The solvent used in the preparation process may be one or more ofdioxane, tetrahydrofuran, pyridine, dichloromethane, chloroform,toluene, acetone, acetonitrile, n-hexane or the like.

The above preparation process may be performed by reacting themethacrylic acid, the methacrylate represented by general formula VI andthe methacryloyl chloride in the presence of an initiator at 50-90° C.for 8-20 hours to obtain the copolymer 1, and then adding dropwise thevinyl ether represented by general formula V into the copolymer 1 at35-50° C. over 1-3 hours and reacting for 5-20 hours to obtain the vinylether group-containing copolymer.

The initiator can be one or more of azobisisobutyronitrile (AIBN),azobisisoheptylnitrile, dimethyl azodiisobutyrate, benzoyl peroxide,tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, potassiumpersulfate, ammonium persulfate, and the like.

The invention further relates to use of the above copolymer in thepreparation of a color light blocking agent.

Moreover, the invention further relates to a color light blocking agentcomprising the above vinyl ether group-containing copolymer.

Preferably, the color light blocking agent further comprises a radicalpolymerization initiator and a cationic polymerization initiator.

Wherein, the radical polymerization initiator may be a radicalpolymerization initiator commonly used in the field, for example, one ormore selected from 1-hydroxycyclohexylphenylmethanone (that is, thephoto-initiator 184),2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-acetone (that is, thephoto-initiator 907), and 2-isopropylthiaanthracenone (that is, thephoto-initiator ITX). The cationic polymerization initiator may be acationic polymerization initiator commonly used in the field, forexample, one or more selected from AlCl₃, BF₃, SnCl₄, PAG-201, ZnCl₂ orTiBr₄.

Some examples are listed below to specifically illustrate the copolymerof the invention, however, the invention is not limited thereto. Itshould be noted that the infrared spectra in the invention is measuredby using a 750× type infrared spectrometer of Nicolet Company, and theweight average molecular weight is measured according to GPC method.

Preparation of Vinyl Ether Group-Containing Copolymer Example 1

Under the protection of nitrogen gas, 43.0 g (about 0.5 mol) ofmethacrylic acid, 20.0 g (about 0.2 mol) of methyl methacrylate, 31.4 g(about 0.3 mol) of methacryloyl chloride, 0.9 g ofazobisisobutyronitrile and 1000 g of dioxane were added into a reactioncontainer and heated to 50-90° C. (preferably, about 70° C.). Afterreacting for 8-20 h (preferably, about 12 h), 2-5 drops of hydroquinoneas a polymerization inhibitor were added into the system. Then, thereaction system was cooled to a temperature of 35-50° C. (preferably,about 40° C.), and 0.3 mol of hydroxyethyl vinyl ether was addeddropwise thereto over 1-3 h (preferably, about 2 hours). After theaddition, the reaction was kept for about 10 h and then cooled down toroom temperature. An aqueous methanol solution with a volume ratio of1:1 was added into the reaction system to precipitate white powders. Themixture was filtrated using an air bump and the cake was dried in vacuofor 24 hours to obtain the vinyl ether group-containing copolymer of theinvention.

In the copolymer, the ratio of the molar numbers of the structural unitsrepresented by general formulae I, II and III was 5:2:3, and the weightaverage molecular weight of the obtained copolymer was 16000. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1619 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Example 2

Under the protection of nitrogen gas, 34.4 g (about 0.4 mol) ofmethacrylic acid, 34.2 g (about 0.3 mol) of ethyl methacrylate, 31.4 g(about 0.3 mol) of methacryloyl chloride, 1.0 g ofazobisisobutyronitrile and 1200 g of dioxane were added into a reactioncontainer and heated to about 90° C. After reacting for 15 h, 2-5 dropsof hydroquinone as a polymerization inhibitor were added into thesystem. Then, the reaction system was cooled to a temperature of about35° C., and 0.3 mol of hydroxyethyl vinyl ether was added dropwisethereto over about 1 h. After the addition, the reaction was kept forabout 10 h and then cooled down to room temperature. An aqueous methanolsolution with a volume ratio of 1:1 was added into the reaction systemto precipitate white powders. The mixture was filtrated using an airbump and the cake was dried in vacuo for 24 hours to obtain the vinylether group-containing copolymer of the invention.

In the copolymer, the ratio of the molar numbers of the structural unitsrepresented by general formulae I, II and III was 4:3:3, and the weightaverage molecular weight of the obtained copolymer was 15500. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1617 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Example 3

Under the protection of nitrogen gas, 43.0 g (about 0.5 mol) ofmethacrylic acid, 43.6 g (about 0.2 mol) of 2-cyclobutyl methacrylate,31.4 g (about 0.3 mol) of methacryloyl chloride, 11.8 g of benzoylperoxide and 945 g of dioxane were added into a reaction container andheated to about 50° C. After reacting for 20 h, 2-5 drops ofhydroquinone as a polymerization inhibitor were added into the system.Then, the reaction system was cooled to a temperature of about 50° C.,and 0.3 mol of hydroxyethyl vinyl ether was added dropwise thereto overabout 3 h. After the addition, the reaction was kept for about 10 h andthen cooled down to room temperature. An aqueous methanol solution witha volume ratio of 1:1 was added into the reaction system to precipitatewhite powders. The mixture was filtrated using an air bump and the cakewas dried in vacuo for 24 hours to obtain the vinyl ethergroup-containing copolymer of the invention.

In the copolymer, the ratio of the molar numbers of the structural unitsrepresented by general formulae I, II and III was 5:2:3, and the weightaverage molecular weight of the obtained copolymer was 17000. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1619 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Example 4

Under the protection of nitrogen gas, 34.4 g (about 0.4 mol) ofmethacrylic acid, 22.8 g (about 0.2 mol) of ethyl methacrylate, 41.8 g(about 0.4 mol) of methacryloyl chloride, 1.0 g of ammonium persulfateand 1000 g of tetrahydrofuran were added into a reaction container andheated to about 70° C. After reacting for 12 h, 2-5 drops ofhydroquinone as a polymerization inhibitor were added into the system.Then, the reaction system was cooled to a temperature of about 40° C.,and 0.4 mol of 2-aminoethyl vinyl ether was added dropwise thereto overabout 2 h. After the addition, the reaction was kept for about 10 h andthen cooled down to room temperature. An aqueous methanol solution witha volume ratio of 1:1 was added into the reaction system to precipitatewhite powders. The mixture was filtrated using an air bump and the cakewas dried in vacuo for 24 hours to obtain the vinyl ethergroup-containing copolymer of the invention.

In the copolymer, the ratio of the molar numbers of the structural unitsrepresented by general formulae I, II and III was 4:2:4, and the weightaverage molecular weight of the obtained copolymer was 14000. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1619 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Example 5

Under the protection of nitrogen gas, 51.7 g (about 0.6 mol) ofmethacrylic acid, 20.0 g (about 0.2 mol) of methyl methacrylate, 20.9 g(about 0.2 mol) of methacryloyl chloride, 0.9 g ofazobisisobutyronitrile and 1000 g of dioxane were added into a reactioncontainer and heated to about 50° C. After reacting for 15 h, 2-5 dropsof hydroquinone as a polymerization inhibitor were added into thesystem. Then, the reaction system was cooled to a temperature of about35° C., and 0.2 mol of hydroxybutyl vinyl ether was added dropwisethereto over 1-3 h (preferably, about 2 hours). After the addition, thereaction was kept for about 10 h and then cooled down to roomtemperature. An aqueous methanol solution with a volume ratio of 1:1 wasadded into the reaction system to precipitate white powders. The mixturewas filtrated using an air bump and the cake was dried in vacuo for 24hours to obtain the vinyl ether group-containing copolymer of theinvention.

In the copolymer, the ratio of the molar numbers of the structural unitsrepresented by general formulae I, II and III was 6:2:2, and the weightaverage molecular weight of the obtained copolymer was 14600. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1618 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Example 6

Under the protection of nitrogen gas, 51.6 g (about 0.6 mol) ofmethacrylic acid, 33.6 g (about 0.2 mol) of cyclohexyl methacrylate,21.0 g (about 0.2 mol) of methacryloyl chloride, 0.9 g ofazobisisobutyronitrile and 1000 g of dioxane were added into a reactioncontainer and heated to about 70° C. After reacting for 8 h, 2-5 dropsof hydroquinone as a polymerization inhibitor were added into thesystem. Then, the reaction system was cooled to a temperature of about40° C., and 0.2 mol of hydroxyethyl vinyl ether was added dropwisethereto over about 3 h. After the addition, the reaction was kept forabout 10 h and then cooled down to room temperature. An aqueous methanolsolution with a volume ratio of 1:1 was added into the reaction systemto precipitate white powders. The mixture was filtrated using an airbump and the cake was dried in vacuo for 24 hours to obtain the vinylether group-containing copolymer of the invention.

In the copolymer, the ratio of the molar numbers of the structural unitsrepresented by general formulae I, II and III was 3:1:1, and the weightaverage molecular weight of the obtained copolymer was 5000. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1618 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Example 7

Under the protection of nitrogen gas, 32.6 g (about 0.38 mol) ofmethacrylic acid, 50.0 g (about 0.5 mol) of methyl methacrylate, 12.6 g(about 0.12 mol) of methacryloyl chloride, 1.1 g ofazobisisobutyronitrile and 1000 g of dioxane were added into a reactioncontainer and heated to about 80° C. After reacting for about 15 h, 2-5drops of hydroquinone as a polymerization inhibitor were added into thesystem. Then, the reaction system was cooled to a temperature of 35° C.,and 0.12 mol of hydroxyethyl vinyl ether was added dropwise thereto overabout 1 h. After the addition, the reaction was kept for about 10 h andthen cooled down to room temperature. An aqueous methanol solution witha volume ratio of 1:1 was added into the reaction system to precipitatewhite powders. The mixture was filtrated using an air bump and the cakewas dried in vacuo for 24 hours to obtain the vinyl ethergroup-containing copolymer of the invention.

In the copolymer, the ratio of the molar numbers of the structural unitsrepresented by general formulae I, II and III was 3:4:1, and the weightaverage molecular weight of the obtained copolymer was 17000. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1619 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Example 8

Under the protection of nitrogen gas, 49.0 g (about 0.57 mol) ofmethacrylic acid, 7.0 g (about 0.07 mol) of methyl methacrylate, 37.6 g(about 0.36 mol) of methacryloyl chloride, 0.9 g ofazobisisobutyronitrile and 1000 g of dioxane were added into a reactioncontainer and heated to 90° C. After reacting for 20 h, 2-5 drops ofhydroquinone as a polymerization inhibitor were added into the system.Then, the reaction system was cooled to a temperature of 40° C., and0.36 mol of hydroxyethyl vinyl ether was added dropwise thereto overabout 1 h. After the addition, the reaction was kept for about 10 h andthen cooled down to room temperature. An aqueous methanol solution witha volume ratio of 1:1 was added into the reaction system to precipitatewhite powders. The mixture was filtrated using an air bump and the cakewas dried in vacuo for 24 hours to obtain the vinyl ethergroup-containing copolymer of the invention.

In the copolymer, the ratio of the molar numbers of the structural unitsrepresented by general formulae I, II and III was 8:1:5, and the weightaverage molecular weight of the obtained copolymer was 16500. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1619 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Example 9

Under the protection of nitrogen gas, 40.4 g (about 0.47 mol) ofmethacrylic acid, 24.0 g (about 0.24 mol) of methyl methacrylate, 30.3 g(about 0.29 mol) of methacryloyl chloride, 1.0 g ofazobisisobutyronitrile and 1000 g of dioxane were added into a reactioncontainer and heated to about 50° C. After reacting for about 12 h, 2-5drops of hydroquinone as a polymerization inhibitor were added into thesystem. Then, the reaction system was cooled to a temperature of 35-50°C. (preferably, about 40° C.), and 0.29 mol of hydroxyethyl vinyl etherwas added dropwise thereto over 1-3 h (preferably, about 2 hours). Afterthe addition, the reaction was kept for about 10 h and then cooled downto room temperature. An aqueous methanol solution with a volume ratio of1:1 was added into the reaction system to precipitate white powders. Themixture was filtrated using an air bump and the cake was dried in vacuofor 24 hours to obtain the vinyl ether group-containing copolymer of theinvention.

In the copolymer, the ratio of the molar numbers of structural unitsrepresented by general formulae I, II and III was 8:4:5, and the weightaverage molecular weight of the obtained copolymer was 20000. Anabsorption peak derived from the double bond vibration of the vinylether group could be observed at 1620 cm⁻¹ in the infrared spectroscopy(KBr) of the copolymer.

Comparative Example 1

Under the protection of nitrogen gas, 43.0 g (about 0.5 mol) ofmethacrylic acid, 20.0 g (about 0.2 mol) of methyl methacrylate, 35.4 g(about 0.3 mol) of hydroxyethyl methacrylate, 0.9 g ofazobisisobutyronitrile and 1000 g of dioxane were added into a reactioncontainer and heated to about 70° C. After reacting for 12 h, thereaction system was cooled down to room temperature. An aqueous methanolsolution with a volume ratio of 1:1 was added into the reaction systemto precipitate white powders. The mixture was filtrated using an airbump and the cake was dried in vacuo for 24 hours to obtain themethacrylic copolymer of comparative example 1.

In the copolymer, the ratio of the molar numbers of methacrylic acid,methyl methacrylate, and hydroxyethyl methacrylate was 5:2:3, and theweight average molecular weight of the obtained copolymer was 14300.

Measurement of Acid Value

0.5-3 g of a sample was weighted with an accuracy of 1 mg and placedinto an Erlenmeyer flask. 50 ml of a toluene-absolute methanol (with avolume ratio of 1:1) mixed solvent was sucked with a transfer pipetteand put into the Erlenmeyer flask. The Erlenmeyer flask was shaken untilthe sample was dissolved completely. The solution was cooled to roomtemperature and added with 5 drops of an indicator (0.1% solution ofphenolphthalein in absolute ethanol). The Erlenmeyer flask was placed ona magnetic stirring device and titrated with a potassiumhydroxide-ethanol standard solution until the solution changed to pinkand this color kept for 20 s-30 s without disappearing, which isregarded as the end point. The volume of the potassium hydroxide-ethanolstandard solution consumed was recorded to calculate the acid value.Av=56.1*(V ₁ −V ₂)*c/m

Av: the acid value of the copolymer, mgKOH/g

V₁: the volume (ml) of the potassium hydroxide-ethanol standard solutionconsumed when the sample was tested

V₂: the volume (ml) of the potassium hydroxide-ethanol standard solutionconsumed when a blank was tested

c: the molar concentration (mol/L) of the potassium hydroxide-ethanolstandard solution

m: the mass (g) of the sample

The acid values of the vinyl ether group-containing copolymers obtainedin Examples 1-9 and the acid value of the copolymer of comparativeexample 1 were shown in table 1.

TABLE 1 Example Comparative Example 1 Example 2 Example 3 Example 4Example 5 Example 6 Example 7 Example 8 Example 9 Example 1 Acid value168 129 160 132 195 193 124 190 155 170 (mgKOH/g)

Preparation of Color Light Blocking Agent

According to the compositions and contents as shown in the below Table2, various materials were weighted, placed into a stirring machine andmixed and dispersed for about 10 hours. The mixture was filtered using afiltering film with a pore diameter of 0.2 μm to obtain a filtrate, thatis, the color light blocking agent.

It should be noted that the pigment used in the above color lightblocking agent can be other pigments commonly used in the field, suchas, CI Pigment Yellow, CI Pigment Orange, CI Pigment Violet, or thelike. With regard to the multi-functional monomer, other compoundscontaining two or more double bonds commonly used in the field, such as,ethylene glycol dimethacrylate or the like, can also be used. Thesolvent used in the color light blocking agent can be the solventscommonly used, such as, tetrahydrofuran, cyclohexanone,N,N-dimethylformamide, ethylene glycol ethyl ether acetate, acetone,propylene glycol methyl ether acetate, or the like. The above solventscan be used alone, or used in a combination of two or more.

Next, the color light blocking agent was spin-coated on a silicon wafer,a glass or the like using a gluing machine to form a color lightblocking agent layer. The film was subjected to pre-baking at 70° C. for30 min, exposing, developing at 23° C. for 30 s, and post baking at 120°C. for 30 min in turn. Finally, the exposed color light blocking agentlayer was developed. As a developer for the developing process, therecan be used an alkaline developer, including a 0.1-10 wt % aqueoussolution of an alkaline compound such as sodium hydroxide, potassiumhydroxide, sodium carbonate, tetramethyl ammonium hydroxide, or thelike.

Measurement of Sensitivity

Using the above exposing and developing method, the minimal exposingamount required for obtaining a 20 μm pattern using the above colorlight blocking agent was measured, which was regarded as the sensitivityof the color light blocking agent.

Evaluation for Film-Forming Property

Firstly, a color light blocking agent was coated onto a silicon waferusing a gluing machine to form a color light blocking agent layer. Thesample was pre-baked at 90° C. for 60 s and weighted using an analyticalbalance under a shading condition to obtain W1. The silicon wafer wasdipped in a 2.38 wt % tetramethyl ammonium hydroxide solution at 23° C.for 60 s, washed with water, dried and weighted to obtain W2. Then, theresidual color light blocking agent was removed by washing, and thewashed sample was dried and weighted to obtain W3. A residual film ratiowas calculated according to the following formula. When the residualfilm ratio of the color light blocking agent was 95% or more, thefilm-forming property thereof was superior; when the residual film ratioof the color light blocking agent was 85 or more and less than 95%, thefilm-forming property thereof was common.Residual film ratio=(W2−W3)/(W1−W3)*100%

TABLE 2 Color light Multi-functional blocking Copolymer InitiatorPigment monomer Solvent Sensitivity Film-forming agent (g) (g) (g) (g)(g) (mJ/cm²) property Example 10 Example 1 907/PAG CI DPHATetrahydrofuran 127 Superior (6 g) 201 = 5:1 Pigment (1 g) (42 g) (1.2g) Red 168 (6 g) Example 11 Example 2 907/PAG CI DPHA Tetrahydrofuran132 Superior (6 g) 201 = 5:1 Pigment (1 g) (42 g) (1.2 g) Red 168 (6 g)Example 12 Example 3 907/PAG CI DPHA Propylene 135 Superior (6 g) 201 =6:1 Pigment (1 g) glycol methyl (1.2 g) Red 168 ether acetate (6 g) (42g) Example 13 Example 4 907/PAG CI DPHA Cyclohexanone 139 Common (6 g)201 = 4:1 Pigment (1 g) (42 g) (1.2 g) Red 168 (6 g) Example 14 Example5 907/PAG CI DPHA Tetrahydrofuran 130 Superior (6 g) 201 = 5:1 Pigment(1 g) (42 g) (1.2 g) Red 168 (6 g) Example 15 Example 6 907/PAG CI DPHATetrahydrofuran 146 Superior (6 g) 201 = 5:1 Pigment (1 g) (42 g) (1.2g) Red 168 (6 g) Example 16 Example 7 907/PAG CI DPHA Tetrahydrofuran170 Superior (6 g) 201 = 5:1 Pigment (1 g) (42 g) (1.2 g) Red 168 (6 g)example 17 Example 8 ITX/BF₃ = CI DPHA Propylene 153 Common (6 g) 4:1Pigment (1 g) glycol methyl (1.2 g) Red 168 ether acetate (6 g) (42 g)example 18 Example 9 184/PAG CI DPHA Tetrahydrofuran 158 Superior (6 g)201 = 6:1 Pigment (1 g) (42 g) (1.2 g) Red 168 (6 g) ComparativeComparative 907/AlCl₃ = CI DPHA Propylene 350 Superior Example 2 Example1 5:1 Pigment (1 g) glycol methyl (6 g) (1.2 g) Red 168 ether acetate (6g) (42 g) Note: DPHA bipentaerythritol penta/hexaacrylate; PAG 201(Changzhou Tronly Electronic Material Co. Ltd., with a maximalabsorption wavelength of 301 nm)

As seen from Table 2, the color light blocking agent obtained by usingthe vinyl ether group-containing copolymer of the invention hasexcellent sensitivity, and the film-forming property thereof is superiorin general.

Obviously, those skilled in the art can make various modifications andchanges to the invention without departing from the spirit and scope ofthe invention. Thus, if these modifications and changes fall into thescope of the claims attached and the equivalents thereof, the inventionalso intends to comprise these modifications and changes.

What is claimed is:
 1. The process for preparing a vinyl ethergroup-containing copolymer wherein the copolymer is composed of thestructural units represented by the following general formulae I, II andIII,

wherein R¹ is O or HN, R² is an alkyl group with a carbon atom number of1-4, cyclohexyl or a group represented by the following general IV, inwhich m represents a positive integer of 1-3,

n is a positive integer of 1-4, the molar numbers of the structuralunits represented by the general formulae I, II and III are x, y and z,respectively, and x:y:z=3-8:1-4:1-5, and the weight average molecularweight of the copolymer is 5000-20000, the process comprises the stepsof: (1) copolymerizing methacrylic acid, a methacrylate represented bythe following general formula VI and methacryloyl chloride to obtain acopolymer 1;

(2) adding a vinyl ether represented by the following general formula Vinto the copolymer 1 to obtain the vinyl ether group-containingcopolymer,

wherein R¹ is O or HN, R² is an alkyl group with a carbon atom number of1-4, cyclohexyl or a group represented by the following general formulaIV, in which m represents a positive integer of 1-3,

n is a positive integer of 1-4, wherein the step (1) is performed byreacting methacrylic acid, the methacrylate represented by the generalformula VI and methacryloyl chloride, in the presence of an initiator,at 50-90° C. for 8-20 hours to obtain the copolymer 1; and the step (2)is performed by adding dropwise the vinyl ether represented by thegeneral formula V into the copolymer 1 at 35-50° C. over 1-3 hours andthen reacting for 5-20 hours to obtain the vinyl ether group-containingcopolymer.
 2. The copolymer process according to claim 1, wherein theinitiator in the process is one or more selected fromazobisisobutyronitrile, azobisisoheptylnitrile, dimethylazodiisobutyrate, benzoyl peroxide, tert-butyl peroxybenzoate, methylethyl ketone peroxide, potassium persulfate, ammonium persulfate.